A loud motor boat can be annoying. If you are a hermit crab, however, the sound could be deadly. Last year, researchers discovered that playing boat noise distracted the crabs, preventing them from paying attention to potential predators. It’s just one example of how human-created sounds can interfere with “biologically important decisions about food selection, mate selection, and predator detection,” a new review of animal “attention” finds.

Animals respond to all kinds of sights, sounds and smells, Alvin Aaden Yim Hol Chan and Daniel T. Blumstein of the University of California, Los Angeles, note in the journal Applied Animal Behavior Science. But they use a process called attention to filter out irrelevant information and focus on what’s important. Attention, however, “is finite and limits the total amount of information that can be processed,” the trio notes. And animals become distracted when they have to attend to “peripheral and irrelevant perceived stimuli” – such as human-created noise – “leaving them less able to attend to a stimulus important for survival or reproductive success.”

To help conservation biologists and wildlife managers understand “how attention can be manipulated for management, and understood for conservation,” the duo reviewed studies of attention in a wide range of animals, from mammals to crustaceans. They suggest that “attentional processes are widespread,” and that distracting noises can have both pros and cons for conservation. Industrial facilities and traffic noise may both make it harder for animals to communicate, for instance, and to waste energy due to heightened attention. But humans could also use noise to scare off or “interfere with ‘problem’ animals,” the researchers note. For example, researchers have shown that certain sounds can disrupt the mating of bark pine beetles (Dendroctonus ponderosae), a widespread forest pest.

Overall, “we need studies that aim to better understand the population consequences of distraction on wildlife populations,” the authors conclude. One key question, they add, is whether animals get used to annoying noises, and learn to just tune them out. – David Malakoff | March 19, 2011